There is a need for non-invasive, user-friendly cerebral oxygenation monitoring during one of the most vulnerable stages of life, the neonatal period. Near-infrared spectroscopy (NIRS) is an optically based technique that can be used to non-invasively and continuously monitor brain oxygenation by determining relative changes in oxyhemoglobin (deltaHbO2) and deoxyhemoglobin (deltaHb). NIRS is based upon the use of the modified Beer-Lambert Law to distinguish between deltaHbO2 and deltaHb. By using low power laser diodes to effect the determination of the Beer-Lambert parameters, it will be possible to construct a small, relatively inexpensive NIRS device. This device will find great utility in neonatal centers and holds the promise of applications in other clinical situations where the degree of tissue oxygenation is desired. The primary objectives of this SBIR are 1) to develop a NIRS system to monitor deltaHb, deltaHbO2, and deltaTotalHb, specifically directed to neonatal monitoring, 2) to test the feasibility of a novel hardware design that will reduce cost and power consumption when compared to other available NIRS systems, and 3) to verify equipment safety. PROPOSED COMMERCIAL APPLICATIONS: An instrument that can non-invasively and continuously monitor brain oxygenation changes of the neonate would be a valuable addition to every neonatal intensive care unit or medical facility. In 1995, there were approximately 3.9 million live births in the U.S. Of that, 0.76% of the infants died in the first year [27]. An analysis of the cause of death shows that approximately 74% (21,750 infants) could have benefitted from cerebral oxygenation monitoring. Low birth weight (<2,500 g) is a risk factor associated with poor outcome [24]. In 1995, there were approximately 286,000 live low birth weight infants, with a mortality rate of 6.5% in the first year [27]. NlRS offers improved capability in neonatal monitoring to assist physicians in the care of several hundred thousand neonates and infants a year.